Relief-valves for rock-drills.



T. E. STURTEVANT. RELIEF VALVE FOR ROCK DRILLS.

APPLICATION FILED JAN. 30, 1914.

Patented Feb. 9, l1915.

THOMAS E. STUBT'EVANT, 0F DOVER, NEW JERSEY, PLSIGK'G'G'R Cil@r'EcKIENN-TEBEY DRILL COMPN'Y, 0F DQVEB, NEW JERSEY, iOQRPRTQE F JERSEY.

Application tied Ienuar 50, lei/.

T all whom it may concern Be it known that L'Tnonms E. SroursvAN'r, acitizen of the United States of America, and a resident of Dover,florris county, and State of New Jersey, have invented certain new anduseful Improvements in Relief-Valves for Rockdrills, oi' which thefollowing is e specification, ref-er ence being had to the accompanyingdrew l@ ings, forming a part thereof.

f My invention relates to elastic fluid cngines, and particularly topoweroperated percussive. tools such as rock drills, mining machines andthe like, the operation which is etl'ected by elastic motive fluid under pressure alternately admitted into a workingcylinder uponoppositesides of a reciprocating piston freely mounted therein Oneobject of my invention is to provide in a. device of the aforesaidcharacter, simple and effective means for stopping the machine andblowing fluid through an opening` in the drill steel, for the purpose ofcleaning the cuttings out of the drill hole.

Another object of my invention is to pro-Y vide a read-ily operatedattachment for producing an unbalanced fluid pressure condition in thevalve chest of a drill and causing the valve to move the plunger to thehack end of its stroke and hold it in such position.

Other objects and advantages of my invention will he set forthhereinafter, and in` order that my invention may he thoroughlyunderstood, l will now proceed to describe the same in the followingspecification, and then point ont the novel features thereof in appendedclaims.

Referring to the drawings: Figure l is a central longitudinal section ofa rock drill equipped with my invention. Fig. is a view correspondingrto the middle portion ot' Fig. l, illustratingr the. positions` of theparts when the attachment is actuated. The relief valve of my inventionand thc end of the valve chest to which it is attached are shown insection on a larger scale in Fig. Ei. Figi. l is a sectional view of therelief valve attach nient tkcn on the line 4-4 of Fig. 1%. Fig. 5 is asectional plan view ol the saine. talten on the lino 5-5 of Fig. 4.

In the operation ot' rock drills it becomes necessary at frequentintervals to clean ont the cuttings troni thc hole since they otherwiseimpede the progress of the drillA lVith the attachment of my presentinvention, it

' dei Specification et Letters Eaterit,

serial ne., emesse.

`ry for the operator to actuate in f s er to op the machine n 'elast orthe motive fluid out- .tarte-d automatically es soon 'hilo l have showne, particular fg machine, my invent-ion 'is in i. i hereto.

The u'iacl'une illustrated comprises a cylinder l() in which operates apiston or plunl) haring' a striker or hammer lll at one end, a valichest lli. a .slide valve 18 therein, and in v improved reliet valve Q0at one end ot' the chest. The drill is arranged to operate in a wellknown manner and need not be :laail in detail. llilotive fluid issupplied to they valve chest at TLT-M17 z nd is exhausted from themachine at ll, Ports 19 and 19 connect the valve chest with therespective ends ot the main cylinder l0 and the usual ports 2l und 2lconnect each one of the valve ci; sts with the opposite end of the maincylinder. A cap. 22 is secured to one end of the chest and an end plate23 at the opposite end. rthis end of the chest is shown on a largerscale in Fig. 3. It has secured to it the valve 20. The end of the valvechest is countcrhored at 2l, and e. thimhle Q5 set into it. The tliimolehas ,a Central hole 26 and a cylindrical projection 27 which eX- lendsinto a central hole 28 in the end plate :23, a jv'ielding 'washer 2lihcing tit-ted on the cylindrical projection Z7 rad interposed hetweenthe thimhle and the plate. Thehole 39 in the plate enlarged at its upperond to forni a recess 30 and a valve scat 3l is mounted on the plate andhas a projection which extends into the recess 30. The seat ill has acentral opening 33 of conical form into which tapered ping valve 3l isinsert ed. This valve extends beyond the end of the scat and cons itutesa projection or hutton which may he pressed to open the valve.

-The valve is held on its seat by a. spring 35. which is interposedbetween the thimble 2 The valve seat 31 and 5 and the valve 34;. heplate 23 are both held in position by bolts 3G which extend throughthese memirrs in the usual manner and are screwed into the valve chest.The valve seat is preferably provided with a cross-passage or outlet 4Gas clearly shown in Figs. 4 and 5 and 1m:r

the valve is provided with an annular oove 41 and perforations 42 and 43which orm connecting passages. The arrangement of parts is such that thevalve my be pressed inwardly in opposition to the spring 35 and -when sopressed opens a free passage from the end of the chest through the hole26, the hole 28 and the passages 43 to 40 inclusive, to the atmosphere.f Motive fluid under pressure in the end ofthe valve chest is thusquickl exhausted. The effect of this action wil be evident from theoperation of the machine which will new be described: Assuining that the`parts-occupy the positions in which they are illustrated in Fig. 1,Huid pressure being then admitted from the valve chamber 17 lthrough thepassage 19 to the upper end of the cylinder 10,-the plunger is thusmoved downwardly and the striker is about to deliver a blow to the endof the drill which is, indicated at 13. The lower end of the cylinderis'connected through passage 19 in the usual manner to the exhaust 11.When the plunger reaches the limit of its movement 1n this direction theend of the --passage 21lis uncovered and is connected to connects thelower end of the main c linder pas-(iY` with the inlet `chamber 17through t eA sage 19, the end of the main cylinder being then connectedto exhaust through passage 19. The arrangement of parts and the size ofthe passage 21 and 21* are such that the pressure isrelieved graduallyfrom the ends of the chest.

While the machine is in operation theattendant ma press the extremity ofthe valve 34 wit his fin er in opposition to the spring 35 and as a ovedescribed, a flee passage will immediately `be established from theadjacent end of the valvechest to the atmosphere. These passages aresutliciently large to quickly relieve the pressure in the end of thechest and to cause an upward movement of the. slide valve in such adirection as to holdthe main piston or pluner iii. its velevated ositionas shown in ig. 2. In this posltion, as clearl indicated, a connectionis .established irectly mamas from the inlet chamber 17 of the chestthrough the assa e 19* into the lower end of the cylin er, t encethrough spaces between the striker and a. sleeve or bushing 48 in whichit operates, and out throu h a central hole 49 in the drill. The stri er14 is uted or otherwise arranged to permit the motive fluid to passfreely through the sleeve 48. By this means a strong blast is producedwhich quickly and effectively cleans the drill hole; As soon as pressureis relieved from the valve 34, the valve will be closed by the spring 35and the tool will resume its o eration.

What I c aim is:

1. In a rock drill, the combination with a cylinder, a plunger therein,a valve chest, a loatin slide valve for governing the supsly of uid tothe cylin rill steel, a relief valve biased to closed po'- sition andcontrollable rby the operator'for exhausting the fluid pressure from oneend of the valve chest to stop the drill and blow motive fluid throughthe drill steel.

er, and a hollow'- 2. Ina rock drill, the combination witli a cylinder,a plun er therein, a valve chest, a floating slide va ve for governingthe supply vof fluid to the cylinder, and a hollow drill' steel, ya pushbutton relief valve, a spring tending to hold the valve closed, and anoutwardly extendin valve stem controllable b the operator or opening thevalve and ex austing the fluid pressure from one end of the valve chestto stop the drill and blow motive fluid through the drill steel.`

3. -In a rock drill, the combination with a cylinder, a lunger therein,a valve chest, a fioatingsli e valve for governin the supply of fluid tothe cylinder an a hollow drill steel, a Ipush buttony relief valvecomprising a valve seat constitutin a cap eecured to the valve chest andhaving an outwardly converging taper hole, a. taper plug seated thereinand projecting beyond the seat, a spring tending to seat the plug, saidstem being controllable by the operator -for opening t e valve andexhausting the .fluid pressure from one end of the valve chest to stopthe drill and blow motive Huid through the drill steeL In witnesswhereof, I have hereunto set my hand'in the presence of two subscribingwitnesses, this 26 day of January, 1914.

THOMAS E. STURTEVANT.

Witnesses:

ERNEST W. MARSHALL, R. J. D EARBQRN.

